Spark plug



1624,785 Apn; 12, 1927. D. G. FUCHS L s SPARK PLUG Filed- .Oct. 16, 192;

DRYFP Go S |NQYVENTOR ATTORNEY Patented Apr- 9 I DAVEID Gr. FUCHS, OF PITTSBURGH, PENNSYLVANIA.

SPARK PLUG.

.Apiilication filed October 16, 1923. serial No. 668,925.

This invention relates to spark plugsfor use in internal combustion engines, and more particularly to'a spark plug having a visible spark gap for indicating whether the plug is sparking properly.

One of the main objects ofthe invention is to provide a spark plug of simple construction and operation having a visible indicating spark gap which is connected in series with the firing spark gap in such a manner that a spark cannot pass across the visible spark gap until after sparks havepaswd across the firing spark gaps at the inner end of the plug. A further object is to provide a spark plug by means of which a plurality of sparks may be caused within the cylinder for firing the explosive charge. Further objects will appear from the detail description.

In the drawings Figure 1 is an elevation of the spark plug;

Figure 2 is a central vertical section through the spark plug taken substantially on line 22 of Fig. 3;

Figure 3 is an underneath end view of the spark plug. 7 V

The plug includes a body- 1 of a known construction adapted'to be threaded into the head of a cylinder of an internal combustion engine. This bodyreceives a core 2 of porcelain or other suitable, electrical insulating material, which core is provided, at its central portion, with an annular shoulder 3 which fits into body 1. A' packing gland 4- is threaded into the upper portion of body 1' and bears against shoulder 3 forsecuring core 2 in position. A. terminal pin 5 is secured in gland 4:, the upper end of this pin being spaced away from the upper end of an electrical conductor 6 so as to form a visible spark gap 7. The conductor 6 is encased within core 2' and extends longitudinall'y thereof, this conductorextending be yond the lower end of the core and being bent substantiallyat right angles to form a terminal element or sparking point 8. A second conductor 9 similar to conductor 6 is encased within core 2, thissecond conductor being disposed diametrically opposite to conductor 6 and terminating, at'its upper end,

in a binding post 10 connected to conductor 9 by an inclined portion 9 At its lower end rected oppositely to terminal element 8. central pinor electrode 12 of electrical conducting material is secured within core 2 and" projects below the same,- this pin being positioned between land equidistant from spark points 8 and 11. This provides firing spark gaps 13 an'd'fl between the'c'entral electrode or pin 12 andthe spark points 8 and 11, respectively.

- WVhen the plug constructed in the manner illustrated and described is secured inthe head of the cylinder, the binding post 10 is connected to one side of a suitablesource of electrical energy the other side of which is grounded to the engine, in a'known manner. 10 through conductor 9 and jumps from V spark point 11 across spark gap 14 to pin The current passes from binding post from which point the current jumps-across I visible spark gap 7 to pin 5 and thence to ground and back to the otherside of the battery or other source of electrical energy.

By constructing the plug in this manner I obtain two sparks within the cylinder so as to insure proper firing of the explosive mixture and a third sparkis created across the visible'spark gap 7 so that the user can readily determine at a glance if the plug is firing properly. It is to be. noted that therewillbe no spark across gap 7 until after the current has jumped across the gaps 13 and 14 so as to produce thesparks within the cylinder. By this arrangement, if the plug sparks-across gap 7 this is a reliable.

indication that the plug is sparking properly within the cylinder.

\Vhat. I claim is In a spark plug, a body of electrical conducting material, a core of electrical insulating material mounted in the body, a packing 7 member of electrical conducting material threaded into the body and cooperating therewith to secure the core, a pin' of electrical conducting material secured'in the core and projecting. from the lower end thereof,

twoelectrical conductors carried by the core 7 and insulated thereby from each other and from the pin as well as from the body and ducting material carried by the packing the packing member, said conductors being member, the upper end of the other conducprovided With terminal elements disposed tor projecting beyond the core and being 10 adjacent and at opposite sides of the pin, spaced from said terminal pin to form theremeans for connecting one of the conductors with a visible spark gap.

to one side of a source of supply of electrical In testimony whereof I afiix my signature.

energy, and a terminal pin of electrical eon- DAVID G. FUCHS. 

